Macrophages play a crucial role in responding to injury or infection. Thomas Tapmeier, a researcher at Monash University and Oxford University, recently discussed a study he co-authored in MedicalXpress. The paper delves into the subject of lung macrophages and melanoma.
A more recent editorial paper on the same subject has been authored by Dr. Tapmeier. It was recently published in Oncotarget and titled “A macrophage is a macrophage is a macrophage—in metastasis”. Both studies involved a mouse model of melanoma and highlighted the development of lung macrophages along with metastasized lung colonies in a melanoma mouse model.
Macrophages initially examine their immediate environment, devouring anything unexpected. After ingesting antigens, they present them to T cells, eliciting adaptive immune responses. An adaptive immune response destroys invading pathogens and the toxic molecules they produce. Since the responses are destructive, they should only be used against foreign molecules, not against the host’s molecules. The adaptive immune system has the ability to make this determination.
Dr. Tapmeier commented that macrophages support tissue integrity and take on other essential roles, such as:
- Angiogenesis – forming new blood vessels
- Vascular remodeling – monitoring tissue integrity
- Neural patterning – CNS cells acquire diverse identities
However, he explained that tumors can overtake their powers, as tumors need macrophages to expand beyond a specific size or to metastasize.
Although the primary tumor may respond to treatment, metastasis is not yet treatable and interferes with a patient’s survival. Macrophages are capable of performing a vast array of physiological functions. They activate specific gene repertoires, but surface markers targeting macrophages are still not available. Therefore, Dr. Tapmeier explained that current attempts to counter macrophages must focus on surface receptors that guide the macrophages to infection, growth, or inflammation sites.
